Photographic process and emulsion utilizing cation-active surface active agents



Patented Apr. 23, 1940 UNITED STATES PATENT [OFFICE PHOTOGRAPHIC PROCESS AND EMULSION UTILIZING CATION ACTIVE ACTIVE AGENTS SURFACE No Drawing.

Application January 3, 1938,

I Serial No. 183.230

14 Claims.

This invention relates to photographic materials, more particularly it relates to light sensitive photographic emulsions, still more particularly it relates to light sensitive gelatino -silver halide emulsions containing a specific class of organic compounds. The invention also relates to processing baths for treating such emulsions and to methods of preparing the emulsions.

This invention has as an object the preparation of a photographic emulsion with improved wetting characteristics. A further object isthe preparation of photographic materials such as films or plates with alight sensitive emulsion which contains a non-staining agent having wetting properties.

A still further object is the preparation of photographic films or plates having an emulsion which does not form air bubbles when treated with a developer. Other objects will appear 20 hereinafter. I

The above and other objects are attained according to the herein described invention wherein the development of a light sensitive photographic material such as printing paper, plates and films is carried out in the presenceof (1) a cation active organic compound having the general formula:

wherein X is anon-hydrocarbon radical such as hydroxyl or the negative radical of an acid such as a halogen radical, and the various'Rs are hydrocarbon radicals at least one of which has at least six and preferably 12 to 18 carbon atoms, and at least one of which contains at least one group having a cation Y, and (2) those cation active compounds obtained by intra-molecular 4,0 removal of YX therefrom.

In its preferred embodiment, this invention pertains to cation active quaternary ammonium salts having the general formula wherein X represents a halogen atom, R1 represents an aliphatic hydrocarbon radical containing from 12 to 18 carbon atoms; Ra, Ra and R4 represent aliphatic hydrocarbon radicals each of which contains less than 8 carbon atoms, and in add tion. at least one of the groups represented by R1, R2, R3 and R4 has substituted thereon at least one group containing an acid hydrogen or a derivative thereof, particularly a single carboxyl or sulfonic acid group. This preferred embodiment is also intended to embrace inner salts or anhydrldes of. the aforementioned compounds wherein the halogen atom is removed from the nitrogen nucleusand wherein the hydrogen atom or its equivalent isremoved from the salt-forming substituent, the resulting compounds having a nitrogen nucleus bound through oxygen to one of the substituents represented by R1, R2, R3 and R4.

The preferred open chain compounds as well as those containing a closed chain viz.,. the inner salts or anhydrides may be called neutralized compounds of the general formula set forth in the preceding paragraph since the acid groups, for example, carboxyl orsulfonic groups, may be neutralized with inorganic or organic bases or with the nitrogen atomoi the compound to form inner salts.

I have discovered that lightsen'sitive film elements are much more advantageously processed in the presence of organic compounds of the type hereinbefore cited. This advance in the art of processing manifests itself chiefly by rapid and thorough wettingof the film or plates being processed and a complete absence of entrained air on the light-sensitive element. In order to carry out the invention, the organic compounds contemplated may be incorporated into the light sensitive layer or into the processing bath or into a separate layer coated on the film, plate, etc. to be processed.

The invention may be more readily understood by a consideration of the following illustrative examples, in which the quantities are stated in parts by weight:

Example I To 10,000 parts of a gelatino-silver halide emulsion containing approximately 1600 parts solids were added before coating 2.0 parts of the nitrogen-containing organic compound prepared from alpha-brom stearic acid and trimethylamine (as described in Example I of Downing and Johnson application, Serial No. 13,664, filed Mar. 29, 1935, now Patent No. 2,129,264). The treated emulslon was then coated on cellulose nitrate film in known manner and exposed. When this film was processed in a developing bath containing 2 parts Metol, 100 parts sodium sulfite, 5 parts hydroquinone and 8 parts borax in a total volume of one thousand parts, it was observed that the films could be rapidly immersed without trapping any air bubbles and that instantaneous and uniform wetting occurred. A film coated with a similar emulsion not containing the nitrogenous organic compound described abovewas diillcult to wet and trapped a large number of air bubbles on its surface.

Similar results were obtained with an emulsion containing a thiocarbocyanine iodide as a sensitizing dye.

Ten parts of the-quaternary ammonium compound prepared from sodium chloracetate and dimethyloctadecylamine (described in Example 4 of application, Serial No. 13,664) were added to a gelatino-silver halide emulsion containing 1,000 parts of dry gelatin. After coating the treated emulsion in known manner on cellulose acetate film base, it was observed that a drop of water placed on the surface of the hardened emulsion wetted instantaneously while a drop of water placed in the surface of a film coated with a separate part of the same emulsion to which the said organic compound'had not been added, wetted very slowly.

Example III Two tenths of a part of the reaction product of dimethyl n-dodecylamine and chloracetic acid were added to one liter of the developer described in Example I. This developer was found to prevent completely the formation of air-bells upon the films and plates immersed in it.

Example IV Four parts of the reaction product of -y-dimethylaminobeta-hydroxypropanesulfonate and cetyl bromide were added to 10,000 parts of a gelatin solution containing approximately 10% of gelatin and the resulting solution was coated over the emulsion surface of a panchromatic film. The resulting film element was found to possess excellent wetting characteristics upon treatment with a developer similar to that described in Example I.

Example V Twenty-five parts of N-(n-decyl) prepared by the addition of chloracetic acid to dimethyl n-decylamine, followed by neutralization with potassium hydroxide, were dissolved in a small amount of alcohol and added to 20.000 parts of a gelatino-silver halide emulsion containing approximately 15% solids. After coating on a base of cellulose acetate in known manner, it was found that the film wetted in an exceptionally uniform manner and that the film had also been given a reduced coefficient of friction. This surface lubrication manifested itself in an increased resistance of the film to breaking during projection and an avoidance of the common piling-up of the emulsion on printer gates.

Example VI Five parts of the nitrogen-containing compound prepared from sodium chloracetate and dimethyloleylamine were added to a gelatino-silverhalide emulsion containing approximately 1,000 parts gelatin. A film coated with this was exposed and processed in a developer containing paraphenyla-betaine,

enediamine and "glycin".

entrained air bubbles.

' Example VII ino-silver halide emulsion containing approximately 800 parts of dry gelatin and the resulting solution was coated on a cellulose acetate base in known manner. This film was wetted very well by all the common developers and furthermore exhibited a surface. lubrication.

It is to be understood that the aforementioned examples are illustrative merely of a representative few of the many means of carrying into practical operation the present invention. Since the invention involves a processing of light sensitive elements in the presence of a specific class of organic compounds it follows that the said compounds may be added to the emulsion at any point in the preparation of the emulsion or with any of the emulsion constituents; they may be added to the processing bath or to any coating which is applied over the layer which may form part of a completely processed and finished film, paper or plate. l

The following example illustrates the use of the betaines as a lubricant for completely processed film or paper:

Example VIII Per cent p by weight C- (n-hexadecyl) -u-betaine l5 Glycerine or ethylene glycol.........-..; 5 Ethyl alcoh l I 35 Water 45 where X represents a non-hydrocarbon radical such aschlorine, bromine, iodine or hydroxyl groups and R1, R2, R3 and R4 represent a plurality of hydrocarbon groups or derivatives thereof attached to the nitrogen atom through carbon, at least one of the four groups so attached containing at least 6 carbon atoms and at least one of the said groups being further substituted by at least one acidic, salt-forming group such as carboxyl or sulfonlc acid group.

A few of the radicals coming within the scope of this invention are methyl, ethyl, propyl, iso- The wetting was rapid and uniform and there was a complete absence of propyl, butyl, isobutyl, secondary butyl, amyl,

such manner that the nitrogen atom becomes an integral portion of a heterocyclic ring. It is to be understood that the aforementioned hydrocarbon radicals or derivatives thereof may be the same or dissimilar to one another, and one or more should contain at least 6 carbon atoms. Since at least one of the groups denoted by R is further substituted by at least one acidic, saltforming group, it is readily seen that under certain conditions inner-salt formation or anhydride formation will take place. As examples of preferred salt-forming groups mention is made of sulfonlc acid, sulfuric acid, phosphoric and boric acids. This invention contemplates the use of these compounds in their condensed aswell as uncondensed form. Thus the specific compounds described in Downing and Johnson application. Serial No. 13,664, may be substituted for the compounds of the preceding examples.

As examples of specific compounds which are apparently of 'open chain formulation and may be used in accordance with this invention, I mention l-carboyx-n-heptadecyl trilnethylammonium bromido Dimethylcarboxymothyl n-dodecylammonium chloride l-yydrog-S-sulfonic acid-n-propyl n-hexadecyl dimethylammonium mm 9 .methyl carboxymethyl n-octadecylammonium chloride methyl carboxymethyl n-dccylammonium chloride D methyl carboxymethyl n-tetradecylammonium chloride Dimcthyl carboxymethyl 9,l0-octadeconylammonium chloride l-carboxy-n-heptadccyl pyridinium bromide Z-carboxycthyl dimethy n-octadccylammonium chloride l-mrboxy-n-heptadccyl 2-hydroxyethyl morpholinium bromide Methyl cyclohcxyl n-dodecyl carboxymethylammonium chloride l-carboxy-n-heptodocyl tributylnmmonium bromide Dimethyl carbo ethyl 2-hexyldecylammouium chloride Dimethyl n-oct ecyl 2-carboxyethylammonium iodide l-carboxy-n-undecyl pyridinium bromide Since this invention is particularly directed to compounds of the betaine type it is to be understood that the following instructions which pertain to such compounds are the preferred embodiment hereof. As is well known, betaine is a tetramethylammonium inner salt. It has the following configuration:

N 0 Ha In accordance with the present invention it has been found that the new, class of cation active compounds which may be obtained by substituting for a hydrogen atom of the CH2 group or for the CH: group, itself, in the above-identified betaine formula, a hydrocarbon group or derivative containing at least six and preferably from twelve to eighteen carbon atoms are particularly useful in photographic compositions. It is also contemplated that the aforementioned higher hydrocarbon group may be substituted for one or more of the methyl groups, rather than for the CH2 group. Furthermore, in place of one or more of the methyl groups, shown in said formula, other substituents, as for instance, other alkyl groups or aralkyl, aryl or cycloaliphatic groups may be substituted. In the same manner, the nitrogen nucleus may form an integral part of a heterocyclic ring, such as a pyridine or piperidine ring. Likewise, the carbonyl group may be replaced by the residue of other salt-forming groups than the carboxyl group. For instance, it may be the residue of a sulfonic acid, a sulfuric acid ester, a phosphoric acid or a phosphoric acid ester group.' This carbonyl group, or other salt-forming group may, moreover, be substituted on some other substituent of the compound rather than upon the substituent which contains,

or is, a. long chain hydrocarbon group. Com-' pounds of the essential betaine structure in which the nitrogen atom is separated from the carbonyl group by a single carbon atom are herein denoted as a-betaines. Those irl which the separation is by two carbon atoms as B-betaines etc.

Similarly, if the carbonyl group is replaced by S02 we denote the compounds as sulfobetaines.

The following specific compounds having a betaine formulation are useful and are representative of a large class:

C-n-hexadecyl) a-betaine N- n-(lodecyl) a-betaine N-En-hexadecyl) fl-hydroxy -snliobetaine N n-octadecyl) a-betame N -(n-decyl) a-betaine N-(DJO octadeconyl) u-betaine (J-(n-hexadecyl) pyridinium lat-betaine of the formula N-(n-tetradecyl) a-betaino N-(2-ethylhexyl) a-betaine N-(n-octadocyl) B-bctaine N CH-CuHn I have found that the organic compounds hereinbefore described are remarkably efilcient cation active wetting agents for photographic emulsions. When processing films or plates containing a light sensitive layer or layers (which may or may not be of gelatino-silver halide emulsions) in their presence, it is observed that an immediate and uniform wetting takes place with a complete absence of entrained air. This is a novel and unexpected result since it is known that most wetting agents found effective in other fields have little or no value in connection with photographic emulsions. Since good wetting is of major im portance during the process of development, this process in its primary embodiment considers the application of the hereinbefore described organic compounds in the developing bath or in the emulsions or in a coating of any kind applied over the emulsion, The compounds may be added in a water-alcohol both to the emulsion surface or may be applied by a beading or transfer roller, or the continuous film may pass between rollers. Solutions may be sprayed on or any-conventional coating method may be employed. The compounds have utility in film even aside from development operations. Thus an after treatment renders the film of reduced co-eflicient of friction, particularly when present in conjunction with the image carrying layer.

In the case of color film which is to be processed by means of a color-forming developer it may be conveniently beaded upon one surface. The advantages obtained by the use of the compounds of this invention are apparent in color film processing since it is not desirable to have a large amount of solution is contact with the film because of the instability of the color-forming compounds under the processing conditions. The compounds described above make it possible to form an even coating of the developer to the surface of the film. However, the invention also contemplates the addition of the aforementioned compounds in any processing bath normally applied to photographic films, papers or plates, such as fixing, bleaching, stop baths, etc.

The compounds of this invention are not only useful in gelatino-silver halide emulsions which represent the preferred embodiment hereof but may also be used in other types of light sensitive emulsions, e. g. bichromated colloid layers containing protein binding agents or gelatine layers containing diazonium salts useful in producing photographic images by the diazo type of processes, or in emulsion layers containing salts of leuco bases and esters of leuco bases suitably sensitized for the production of colored images. 7

The use of the compounds of this invention possesses the additional advantage that a smoother coating of an emulsion on a film base is obtained. This is an unexpected and surprising result' and is of major importance since fewer repellent spots and coating streaks are formed. Furthermoie no gummy residues or crystalline deposits are formed.

An additional advantage of this invention resides in the fact that the compounds do not fog a light sensitive emulsion nor do they desensitize the emulsion. The resultant film has a reduced coeificient of friction which is of importance in motion picture photography since the films will slip through the photographic equipment, cameras, projection devices, etc. with greater ease.

- As many apparently widely different embodiments of the invention may be made without departing from the spirit and scope thereof it is to be understood that I do not limit myself to the specific embodiments thereof except as described in the following claims.

I claim:

1. The process which comprises developing light sensitive photographic material in the presence of a cation active compound selected from the class consisting of (1) those of the formula wherein X is a non-hydrocarbon radical taken a from the group consisting of hydroxyl radicals and the negative acid radicals, N is a nitrogen atom, and the various R's are aliphatic hydrocarbon radicals at least one of which has at least six carbon atoms, and at least one of which contains at least one group having a cation Y, and (2) those compounds obtained by intra-molecular removal of YX therefrom.

2. The process which comprises developing light sensitive photographic material in the pres-.

ence of a compound of the general formula Rg\ R: R1- -R4 wherein one of the Rs represents an aliphatic straight hydrocarbon radical containing nine to eighteen carbon atoms and the other a hydrogen atom, R1, is a methylene radical, R2 and Ba represent hydrocarbon radicals having less than eight carbon atoms and Y represents the residue of a salt-forming group taken from the group consisting of -SO2- and -CO.

5. A photographic element comprising an emulsion having in intimate contact therewith an organic compound selected from the class consisting of (1) those of the formula wherein X is a non-hydrocarbon radical taken from the group consisting of hydroxyl radicals and the negative acid radicals, N is a nitrogen atom, and the various R's are aliphatic hydrocarbon radicals at least one of which has at least six carbon atoms, and at least one of which contains at least one group having a cation Y, and (2) those compounds obtained by intramolecular removal of YX therefrom.

6. A photographic element comprising a base member coated with a photographic sensitive emulsion containingv an organic compound selected from the class consisting of (1) those of the formula Ra a wherein X is a non-hydrocarbon radical taken from thelgroup consisting of hydroxyl radicals and the negative acid radicals, N is a nitrogen atom, and the various Rs are aliphatic hydrocarbon radicals at least one of which has at least six carbon atoms, and at least one of which contains at least one group having a cation Y, and (2) those compounds obtained by intramolecular removal of YX therefrom.

7. A photographic element comprising a base member coated with a gelatino-silver halide emulsion containing a neutralized compound of the general formula wherein X represents a negative acid radical, one of the Rs represents an aliphatic hydrocarbon radical having at least 8 carbon atoms and the other a hydrogen atom; R1 represents a radical selected from the group consisting of methylene and polymethylene radicals having less than five carbon atoms, said radicals containing an acid radical, R2 and R: represent aliphatic hydroczrbon radicals having less than eight carbon a oms.

one of the Rs represents an aliphatic hydro- 8. A photographic element comprising a transparent support coated with a photographic sensitive gelatino-silver halide emulsion containing a cyanine dye and a compound of the general formula:

wherein one of the Rs represents an aliphatic straight hydrocarbon radical containing nine to eighteen carbon atoms and the other a hydrogen atom, R1 is a methylene radical, R2 and R3 represent hydrocarbon radicals having less than eight carbon atoms and Y represents the residue of a salt-forming group taken from the group consisting of SO2 and CO-.

9. A developing bath for photographic-sensitive materials containing a developing agent and as an assistant a compound selected from the class consisting of (1) those of the formula wherein X is a non-hydrocarbon radical taken from the group consisting of hydroxyl radicals and the negative acid radicals; N is a nitrogen atom, and the various R's are hydrocarbon radicals at least one of which has at least six carbon atoms, and at least one of which contains at least one group having a cation Y, and (2) those compounds obtained by intra-molecular removal of YX therefrom.

10. A developing bath for light sensitive photographic materials containing a neutralized compound of the general formula:

wherein x represents a negative acid radical,

carbon radical having at least 8 carbon atoms and the other a hydrogen atom; R1 represents a radical selected from the class consisting of methylene and polymethylene radicals having less than five carbon atoms, said radicals containing an acid radical, R2 and R3 represent aliphatic hydrocarbon radicals having less than eight carbon atoms'.

11. A finished photographic element comprising a base member having a photographically produced image thereon and having superimposed thereon a thin film of a compound selected from the class consisting of (1) those of the general formula:

wherein X is a non-hydrocarbon radical taken from the group consisting of hydroxyl radicals and negative acid radicals, N is a nitrogen atom, and the various R's are aliphatic hydrocarbon radicals at least one of which has 12 to 18 carbon atoms and at least one of which contains at least one group having a cation Y, and those compounds obtained by intra-molecular removal of YX therefrom.

12. A photographic element comprising a transparent support coated with a photographicsensitive gelatino-silver halide emulsion containing C-hexadecyl-u-betaine.

13. A photographic element comprising a transparent support coated with a photographic sensitive gelatino-silver halide emulsion containing N-hexadecyl-e-betaine.

14. A photographic element comprising a transparent support coated with a photographic sensitive gelatino-silver halide emulsion containing N- (9,10-octadecylenyl) a-betaine.

pAvm M. woman. 

